Infrared (IR) ink may have optical properties that allow for a low transmittance of visible light and a high transmittance of IR light. As such, IR ink may be applied to a surface of a material that transmits IR light to hide an object positioned behind the material from view while still allowing IR light to pass through the material to the object. In one example, IR ink is applied to an interior surface of cover glass of a device that includes an IR camera. In particular, the IR ink is applied to a transmissive (e.g., see-through) camera window in an otherwise opaque bezel of the cover glass. The camera window is aligned with the IR camera to allow IR light to pass through the cover glass to the IR camera. The IR ink is applied to the camera window to hide the IR camera from view so that the opaque bezel has a uniform appearance. In this and other applications, defects in the IR ink can produce undesirable results, especially if the defects are not known.